中子辐射俘获反应在反应堆运行、核装置设计及核天体物理研究中起重要的作用.4πBaF_(2)探测装置有着高时间分辨能力、低中子灵敏度、高探测效率等优点,适合开展中子辐射俘获反应截面数据的测量.中国原子能科学研究院核数据重点实验室...中子辐射俘获反应在反应堆运行、核装置设计及核天体物理研究中起重要的作用.4πBaF_(2)探测装置有着高时间分辨能力、低中子灵敏度、高探测效率等优点,适合开展中子辐射俘获反应截面数据的测量.中国原子能科学研究院核数据重点实验室建立了伽马全吸收装置(Gamma total absorption facility,GTAF),该装置用28块六棱BaF_(2)晶体和12块五棱BaF_(2)晶体构成了外径25 cm,内径10 cm的球壳,覆盖了95.2%的立体角.利用GTAF在中国散裂中子源Back-n束线上,测量了197Au(n,γ)的反应截面数据.测量数据通过能量筛选、PSD方法、晶体多重性筛选进行了初步本底扣除,随后结合对^(nat)C及空样品的测量数据对本底进行了分析及扣除,获得了197Au俘获反应的产额,利用SAMMY程序拟合得到了^(197)Au在1—100 e V的共振能量、中子共振宽度和伽马共振宽度参数.实验测量结果与ENDF/B-VIII.0数据库符合良好,其共振参数存在一定差异,分析原因可能与GTAF能量分辨率、Back-n的中子能谱测量精度、以及实验本底扣除方法相关,这也是下一步工作的重点.展开更多
目的调试并观察外周静脉输液技术在模拟空运后送环境中的应用效果。方法针对空运后送环境,对静脉输液技术中的穿刺时机、穿刺体位、拔针时机、固定方法、封管时机进行适应性调试,采用便利抽样法,从解放军总医院卫勤护理骨干队伍中选取1...目的调试并观察外周静脉输液技术在模拟空运后送环境中的应用效果。方法针对空运后送环境,对静脉输液技术中的穿刺时机、穿刺体位、拔针时机、固定方法、封管时机进行适应性调试,采用便利抽样法,从解放军总医院卫勤护理骨干队伍中选取10名参试者,利用摇摆平台模拟空运环境评价技术应用效果,比较参试者在分别使用调试前外周静脉输液技术与调试后外周静脉输液技术进行输液操作时的一次穿刺成功率、操作得分与用时、操作难易程度及舒适性。本研究采用交叉对照研究设计,每名参试者均参与两种干预,中间间隔2周清洗期。结果在摇摆平台条件下,调试前较调试后操作用时显著缩短(281.3 s vs.227.6 s,P<0.05),操作得分显著增加(68.5分vs.92.7分,P<0.05),两种方案的一次穿刺成功率、操作难易程度、舒适性比较差异无统计学意义(P>0.05)。结论调试后的外周静脉输液操作方案可有效提高伤员空运后送过程中静脉输液效率,保证伤员静脉治疗安全。展开更多
Accurate assessment of crowd evacuation inside the post-earthquake environment is critical from many perspectives,but this issue receives much less attention compared to the seismic losses of structural and non-struct...Accurate assessment of crowd evacuation inside the post-earthquake environment is critical from many perspectives,but this issue receives much less attention compared to the seismic losses of structural and non-structural components.This could be attributed to the fact that post-earthquake evacuation analysis is complex due to the interaction between human behavior and the actual built environment induced by different building contents.This study attempts to tackle this problem by investigating the impacts of different building contents on post-earthquake evacuation time by using an agent-based model that considers turning behavior.To this end,the agent-based model is first described,including:properties of the agent-based model with turning behavior,key aspects in its formulation considering different evacuation stages,and influence of different building contents(namely,debris from partition walls and ceiling systems,and various types of equipment)on the agent’s behavior.Subsequently,a school building is used as a benchmark problem to validate the model without earthquake,and the findings indicate that the agent-based model can match the real safety drill results reasonably well.After the validation,the school building is subsequently designed in accordance with modern seismic design codes,and the influence of debris and equipment on post-earthquake evacuation time is quantitatively studied using a suite of pulse-type ground motions as input.Based on this case study,recommendations are made for structural and architectural designers in an effort to reduce the potential evacuation time.Specifically,debris induced by partition walls or ceiling systems should be controlled as it has the greatest impact on the total evacuation time.展开更多
文摘中子辐射俘获反应在反应堆运行、核装置设计及核天体物理研究中起重要的作用.4πBaF_(2)探测装置有着高时间分辨能力、低中子灵敏度、高探测效率等优点,适合开展中子辐射俘获反应截面数据的测量.中国原子能科学研究院核数据重点实验室建立了伽马全吸收装置(Gamma total absorption facility,GTAF),该装置用28块六棱BaF_(2)晶体和12块五棱BaF_(2)晶体构成了外径25 cm,内径10 cm的球壳,覆盖了95.2%的立体角.利用GTAF在中国散裂中子源Back-n束线上,测量了197Au(n,γ)的反应截面数据.测量数据通过能量筛选、PSD方法、晶体多重性筛选进行了初步本底扣除,随后结合对^(nat)C及空样品的测量数据对本底进行了分析及扣除,获得了197Au俘获反应的产额,利用SAMMY程序拟合得到了^(197)Au在1—100 e V的共振能量、中子共振宽度和伽马共振宽度参数.实验测量结果与ENDF/B-VIII.0数据库符合良好,其共振参数存在一定差异,分析原因可能与GTAF能量分辨率、Back-n的中子能谱测量精度、以及实验本底扣除方法相关,这也是下一步工作的重点.
文摘目的调试并观察外周静脉输液技术在模拟空运后送环境中的应用效果。方法针对空运后送环境,对静脉输液技术中的穿刺时机、穿刺体位、拔针时机、固定方法、封管时机进行适应性调试,采用便利抽样法,从解放军总医院卫勤护理骨干队伍中选取10名参试者,利用摇摆平台模拟空运环境评价技术应用效果,比较参试者在分别使用调试前外周静脉输液技术与调试后外周静脉输液技术进行输液操作时的一次穿刺成功率、操作得分与用时、操作难易程度及舒适性。本研究采用交叉对照研究设计,每名参试者均参与两种干预,中间间隔2周清洗期。结果在摇摆平台条件下,调试前较调试后操作用时显著缩短(281.3 s vs.227.6 s,P<0.05),操作得分显著增加(68.5分vs.92.7分,P<0.05),两种方案的一次穿刺成功率、操作难易程度、舒适性比较差异无统计学意义(P>0.05)。结论调试后的外周静脉输液操作方案可有效提高伤员空运后送过程中静脉输液效率,保证伤员静脉治疗安全。
文摘Accurate assessment of crowd evacuation inside the post-earthquake environment is critical from many perspectives,but this issue receives much less attention compared to the seismic losses of structural and non-structural components.This could be attributed to the fact that post-earthquake evacuation analysis is complex due to the interaction between human behavior and the actual built environment induced by different building contents.This study attempts to tackle this problem by investigating the impacts of different building contents on post-earthquake evacuation time by using an agent-based model that considers turning behavior.To this end,the agent-based model is first described,including:properties of the agent-based model with turning behavior,key aspects in its formulation considering different evacuation stages,and influence of different building contents(namely,debris from partition walls and ceiling systems,and various types of equipment)on the agent’s behavior.Subsequently,a school building is used as a benchmark problem to validate the model without earthquake,and the findings indicate that the agent-based model can match the real safety drill results reasonably well.After the validation,the school building is subsequently designed in accordance with modern seismic design codes,and the influence of debris and equipment on post-earthquake evacuation time is quantitatively studied using a suite of pulse-type ground motions as input.Based on this case study,recommendations are made for structural and architectural designers in an effort to reduce the potential evacuation time.Specifically,debris induced by partition walls or ceiling systems should be controlled as it has the greatest impact on the total evacuation time.
